To the Editor.—The article on sinusitis by Williams and Simel1 is a valuable contribution, but the authors overstate their case in two areas.First, they cite two studies of maxillary sinusitis2,3 to support their claim that "randomized trials have shown that sinusitis requires antibiotics for rapid resolution." The word "requires" is too strong here, since a majority of untreated subjects in both studies were improved or cured at 10 days. Moreover, one was a pediatric study that may not be applicable to adults.2 The other was an adult study with methodologic weaknesses.3 A primary end point was "subjective" improvement, but patients and investigators were not blinded to treatment; and the "nasal decongestant only" group had more bilateral sinusitis and completely opacified sinuses than the lincomycin group, suggesting that more complicated cases might have been assigned to the no-antibiotic group. Interestingly, an authority cited by Williams